Context: Volatile anaesthetics may have direct cardioprotective properties due to effects similar to ischaemic preconditioning and postconditioning. Clinical results in cardiac surgery patients are controversial and may be related to the timing of administration of anaesthetics intraoperatively.
Objective: We hypothesised that the cardioprotective effect of sevoflurane in coronary bypass graft surgical patients would be greater if administration during anaesthesia continued in the ICU for at least 4 h postoperatively until weaning from mechanical ventilation.
Design: Double-blind, double-dummy, prospective, randomised and controlled clinical trial.
Setting: In a single centre between June 2006 and June 2007.
Patients: Seventy-five adult patients were assigned randomly to receive anaesthesia and postoperative sedation either with propofol (control, n = 37) or sevoflurane (n = 36).
Interventions: Myocardial biomarkers were measured before surgery, at the time of admission to the intensive care unit and at 6, 24, 48 and 72 h. The need for inotropic support, and lengths of stay in the intensive care unit and hospital were also recorded.
Main outcome measures: Elevation of myocardial biomarkers was the primary endpoint. The secondary endpoints were haemodynamic events and lengths of stay in the intensive care unit and hospital.
Results: Necrosis biomarkers increased significantly in the postoperative period in both groups with no significant differences at any time. Inotropic support was needed in 72.7 and 54.3% of patients in the propofol and sevoflurane groups, respectively (P = 0.086). There were no significant differences in haemodynamic variables, incidence of arrhythmias, myocardial ischaemia or and lengths of stay in the ICU and hospital between the two groups.
Conclusion: In patients undergoing coronary bypass graft surgery, continuous administration of sevoflurane as a sedative in the ICU for at least 4 h postoperatively did not yield significant improvements in the extent and time course of myocardial damage biomarkers compared to propofol.